Electro-mechanical dispensers employing an electric motor to transport toweling during a dispensing operation are well known. Such arrangements include both dispensers which are manually actuated, as by means of a push button, and those employing a sensor, such as a sensor sensing proximity of a user's hand, to initiate operation.
U.S. Pat. No. 6,820,785 issued Nov. 23, 2004, discloses an electro-mechanical roll towel dispenser including a housing with a roll carrier disposed therein to rotatably support a roll of towel material. An electro-mechanical feed mechanism is disposed in the housing to dispense measured sheets of the towel material. The feed mechanism operates in a first mechanical operational mode wherein the towel sheets are dispensed by a user grasping and pulling on a tail of the towel material extending from the housing, and a second electrical operational mode wherein a measured length of a next sheet is automatically fed from the housing to define the tail for the next user.
The dispenser of U.S. Pat. No. 6,820,785 includes a sensor for detecting a parameter that is changed by an initial pull exerted on a tail of a web of material extending from the opening of the dispenser. The sensor also generates a signal sent from the sensor to a control circuit or circuitry causing the motor employed in the apparatus to drive the feed mechanism until a measured length of web material that includes the tail of web material has been fed from the dispenser in the form of a measured sheet for subsequent removal by the user.
Similar devices are disclosed in U.S. Pat. No. 3,730,409 and Patent Publication Document WO 00/63100. The devices of these latter two documents have sensors for detecting movement of a tail end of web material such that the feed mechanism is activated in response to detecting the movement.
U.S. Pat. No. 8,382,026, issued Feb. 23, 2013, relates to a multi-function paper towel dispenser selectively operable to dispense paper toweling from a roll of paper toweling employing a plurality of alternative operational modes. The desired mode of operation can be selected utilizing control switches associated with sensor structure and electronic control circuitry of the dispenser. The multi-function paper towel dispenser is characterized not only by its versatility, but by its relative simplicity, ease of use and reliability in any of the operational modes selected. Two of the modes are a paper hidden mode and a paper exposed mode, each of which utilizes sensor structure in combination with electronic control circuitry to operate an electric motor driven rotatable toweling support roller to partially cut and dispense the paper toweling. The electric motor is also utilized to rotate the paper toweling support roller when not employing the sensor structure, the motor essentially operating in a hybrid mode wherein a pull force exerted on the toweling tail initiates rotation of the toweling support roller, the electric motor then being energized to reduce the pull force required by a user to effect final dispensing of a towel. Furthermore, a user can manually rotate the paper toweling support roller to effect dispensing of a towel in any of the modes.
The sensor structure of the multi-function paper towel dispenser is operatively associated with the electric motor to energize the electric motor and cause rotation of the toweling support roller to transport the paper toweling for dispensing from the dispenser in either a first mode of operation wherein the electric motor is energized responsive to the sensor structure sensing positioning of a user's hand at a predetermined location external of the housing or in a second mode of operation wherein the electric motor is energized responsive to the sensor structure sensing the removal of a toweling tail from a location external of the housing.
U.S. Pat. No. 8,555,761 discloses another type of “hybrid” mode wherein an electric motor provides a tail if needed. The term “hybrid” encompasses either motor assist type, which could be used in one dispenser, if desired, using a selector switch.
A common feature of electro-mechanical paper toweling material dispensers is an electric motor which is operatively associated with a rotatable paper sheet support roller and which starts and stops to deliver the leading end of the toweling to a desired position (which may be either within the dispenser housing in certain types of dispenser operations or outside the dispenser housing in other types of dispenser operations).
It is important to provide consistent length of the towel portion to be dispensed and thus uniform placement of the leading end of the towel portion. This is true regardless of cutter blade type employed in a dispenser, whether fixed or toweling support roller mounted. Consistent towel portion length is especially useful in certain dispenser types allowing a motor assist mode wherein an overrun can trigger a second sheet to dispense.
As will be described below, the present invention utilizes dynamic braking in a unique combination with certain other paper sheet material dispenser apparatus components. While dynamic braking structures are known, use of such structures with paper sheet dispenser apparatus as disclosed herein is novel.